Choosing Electric Motors for the Robot Arm

a year ago

The article discusses the selection of electric motors for a robotic arm, focusing on the Viper X 300 S manipulator.
Trossen Robotics used DYNAMIXEL XM430-W350 and XM540-W270 servo motors, with stall torques of 4 Nm and 10 Nm respectively.
The total cost for 9 servo motors is $3,590, making it expensive for an affordable manipulator.
Kinematic calculations show a need for drives with 8 Nm torque at the base, considering effective torque is about half the stall torque.
Different types of servo drives are considered: stepper motors (Nema 17, Nema 23), PWM motors (Dsservo 160 kg*cm), and UART motors (Feetech STS 3215-C01).
Key indicators for motor selection include torque, precision, current, voltage, feedback, weight, and cost.
Engine torque is defined as the product of force and distance, crucial for lifting heavy loads.
Positioning accuracy in robotics is vital, with repeatability and absolute accuracy being key metrics.
Feedback sensors include Hall Effect sensors, resolvers, potentiometers, optical encoders, and magnetic encoders for position, and current and temperature sensors for monitoring.
Stepper motors are less favorable due to their size, weight, lower torque, and positioning accuracy compared to servo motors.
PWM motors lack feedback and precise positioning, while UART motors offer better accuracy and feedback but at a higher cost.
Testing revealed issues with backlash and overheating in servo motors, with a critical temperature threshold of 71°C.

Hasty Briefsbeta